[FUG-BR] Valor aconselhavel para variável HZ

[Fabricio Lima]

+ ab (apache bench)

Lembrando q para maquinas virtuais, reduzem este parametro.

Veja isso tb:

However, in FreeBSD 9, the "dynamic tick mode" (aka "tickless mode") is the
default, controlled by the kern.eventtimer.periodic setting which defaults
to 0 (read: tickless mode).

This year FreeBSD 10-HEAD got a new reincarnation of the kernel event
timers backend callout(9)
<https://www.freebsd.org/cgi/man.cgi?query=callout&sektion=9>, no more
limited by or even related to Hz rate.

[ ]'s
Fabricio Lima
When your hammer is C++, everything begins to look like a thumb.

2014-11-06 11:55 GMT-02:00 Paulo Henrique - BSDs Brasil <
paulo.rddck em bsd.com.br>:

>
>
> Enviado do meu smartphone Sony Xperia™
>
> ---- Fabricio Lima escreveu ----
>
> > Edinilson, vc está certo...
> > eu tb mexia mais nisso na epoca do 6, 7, 8..
> >
> > Hj eles ajustaram tanta coisa (9 e 10)
> > q talvez o default seja melhor q um 7 tunado...
> >
> > (minha documentaçao caducou)
> >
> > testar, testar, testar...
> >
> > [ ]'s
> > Fabricio Lima
> > When your hammer is C++, everything begins to look like a thumb.
> >
> > 2014-11-05 16:44 GMT-02:00 Edinilson - ATINET <edinilson em atinet.com.br>:
> >
> > > ----- Original Message ----- From: "Paulo Henrique - BSDs" <
> > >> paulo.rddck em bsd.com.br>
> > >> To: ""Lista Brasileira de Discussão sobre FreeBSD (FUG-BR)"" <
> > >> freebsd em fug.com.br>
> > >> Sent: Wednesday, November 05, 2014 3:58 PM
> > >> Subject: [FUG-BR] Valor aconselhavel para variável HZ
> > >>
> > >> Saudações,
> > >>
> > >> Gostaria de saber se alguém trabalha com a variável HZ com o valor
> > >> superior a 2000, caso sim o ambiente fica estável, há uma melhora no
> > >> desempenho do sistema e da rede ?
> > >> Sei que a mesma interfere quanto ao uso da bateria em portáteis
> contudo a
> > >> duvida é restrita a servidores.
> > >> Aumentar o valor da mesma em um servidor com 12 Cores / 24 Threads com
> > >> 32Gbytes de ram melhorará o desempenho.
> > >> Abaixo tem os dados do sistema atualmente.
> > >> O HZ do sistema está em 2000.
> > >>
> > >> uname -a
> > >> FreeBSD xxxxx 10.0-STABLE FreeBSD 10.0-STABLE #0 r269344: Thu Jul 31
> > >> 14:39:46 BRT 2014
> > >> netstat -m
> > >> yyyyyyy em xxxxx:/usr/obj/usr/src/sys/XXXXXXXXXXX amd64
> > >> 11204/15571/26775 mbufs in use (current/cache/total)
> > >> 1023/9825/10848/2036062 mbuf clusters in use (current/cache/total/max)
> > >> 1023/9512 mbuf+clusters out of packet secondary zone in use
> > >> (current/cache)
> > >> 0/548/548/1018031 4k (page size) jumbo clusters in use
> > >> (current/cache/total/max)
> > >> 0/0/0/301638 9k jumbo clusters in use (current/cache/total/max)
> > >> 0/0/0/169671 16k jumbo clusters in use (current/cache/total/max)
> > >> 4847K/25734K/30581K bytes allocated to network (current/cache/total)
> > >> 0/0/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters)
> > >> 0/0/0 requests for mbufs delayed (mbufs/clusters/mbuf+clusters)
> > >> 0/0/0 requests for jumbo clusters delayed (4k/9k/16k)
> > >> 0/0/0 requests for jumbo clusters denied (4k/9k/16k)
> > >> 0 requests for sfbufs denied
> > >> 0 requests for sfbufs delayed
> > >> 9966280 requests for I/O initiated by sendfile
> > >>
> > >> uptime
> > >> 15:47 up 86 days, 19:40, 1 user, load averages: 8,15 8,86 9,27
> > >>
> > >>
> > >> Alguns tunnings que já foi feito no sistema.
> > >>
> > >> # $FreeBSD: stable/10/etc/sysctl.conf 112200 2003-03-13 18:43:50Z mux
> $
> > >> #
> > >> # This file is read when going to multi-user and its contents piped
> thru
> > >> # ``sysctl'' to adjust kernel values. ``man 5 sysctl.conf'' for
> details.
> > >> #
> > >>
> > >> # Uncomment this to prevent users from seeing information about
> processes
> > >> that
> > >> # are being run under another UID.
> > >> #security.bsd.see_other_uids=0
> > >>
> > >> kern.maxfiles=1000000
> > >>
> > >> # Otimizacoes de rede.
> > >> #kern.ipc.nmbclusters=131072 # 128Mb para buffer de rede - Ficou
> instavel
> > >> valor definido pelo sistema.
> > >> kern.ipc.maxsockbuf=33554432
> > >> net.inet.tcp.sendbuf_max=33554432
> > >> net.inet.tcp.recvbuf_max=33554432
> > >> net.inet.tcp.sendspace=1048576 # default 65536
> > >> net.inet.tcp.recvspace=1048576 # default 32768
> > >> net.inet.tcp.sendbuf_inc=1048576 # 8192 default
> > >> net.inet.tcp.recvbuf_inc=1048576 # 16384 default
> > >> kern.ipc.somaxconn=4096 # 128 default
> > >> net.inet.tcp.syncache.rexmtlimit=1
> > >> net.inet.tcp.syncookies=1
> > >>
> > >> # COnfigura▒▒es de Seguran▒a
> > >> # General Security and DoS mitigation.
> > >> net.inet.ip.check_interface=1 # verify packet arrives on correct
> interface
> > >> net.inet.ip.portrange.randomized=1 # randomize outgoing upper ports
> > >> net.inet.ip.process_options=0 # IP options in the incoming packets
> will
> > >> be ignored
> > >> net.inet.ip.random_id=1 # assign a random IP_ID to each packet leaving
> > >> the system
> > >> net.inet.ip.redirect=0 # do not send IP redirects
> > >> net.inet.ip.accept_sourceroute=0 # drop source routed packets since
> they
> > >> can not be trusted
> > >> net.inet.ip.sourceroute=0 # if source routed packets are accepted the
> > >> route data is ignored
> > >> #net.inet.ip.stealth=1 # do not reduce the TTL by one(1) when a
> packets
> > >> goes through the firewall
> > >> net.inet.icmp.bmcastecho=0 # do not respond to ICMP packets sent to IP
> > >> broadcast addresses
> > >> net.inet.icmp.maskfake=0 # do not fake reply to ICMP Address Mask
> Request
> > >> packets
> > >> net.inet.icmp.maskrepl=0 # replies are not sent for ICMP address mask
> > >> requests
> > >> net.inet.icmp.log_redirect=0 # do not log redirected ICMP packet
> attempts
> > >> net.inet.icmp.drop_redirect=1 # no redirected ICMP packets
> > >> #net.inet.icmp.icmplim=50 # 50 ICMP packets per second. a reasonable
> > >> number for a small office.
> > >> #net.inet.tcp.delayed_ack=1 # always employ delayed ack, 6 packets
> get 1
> > >> ack to increase bandwidth
> > >> net.inet.tcp.drop_synfin=1 # SYN/FIN packets get dropped on initial
> > >> connection
> > >> net.inet.tcp.ecn.enable=1 # explicit congestion notification (ecn)
> > >> warning: some ISP routers abuse it
> > >> net.inet.tcp.fast_finwait2_recycle=1 # recycle FIN/WAIT states quickly
> > >> (helps against DoS, but may cause false RST)
> > >> net.inet.tcp.icmp_may_rst=0 # icmp may not send RST to avoid spoofed
> > >> icmp/udp floods
> > >> net.inet.tcp.maxtcptw=15000 # max number of tcp time_wait states for
> > >> closing connections
> > >> net.inet.tcp.msl=5000 # 5 second maximum segment life waiting for an
> ACK
> > >> in reply to a SYN-ACK or FIN-ACK
> > >> net.inet.tcp.path_mtu_discovery=0 # disable MTU discovery since most
> > >> ICMP packets are dropped by others
> > >> net.inet.tcp.rfc3042=0 # disable the limited transmit mechanism which
> can
> > >> slow burst transmissions
> > >> #net.inet.tcp.sack.enable=1 # sack disabled? http://www.ibm.com/
> > >> developerworks/linux/library/l-tcp-sack/index.html
> > >> net.inet.udp.blackhole=1 # drop udp packets destined for closed
> sockets
> > >> net.inet.tcp.blackhole=2 # drop tcp packets destined for closed ports
> > >> #net.route.netisr_maxqlen=4096 # route queue length defaults 4096
> (rtsock
> > >> using "netstat -Q")
> > >> security.bsd.see_other_uids=0 # hide processes for root from user
> uid's
> > >>
> > >> ## Configuracoes de envio
> > >>
> > >> net.local.stream.sendspace=164240
> > >> net.local.stream.recvspace=164240
> > >>
> > >> ## Configuracoes contra spoof
> > >>
> > >> net.inet.ip.rtexpire=60 # 3600 secs
> > >> net.inet.ip.rtminexpire=2 # 10 secs
> > >> net.inet.ip.rtmaxcache=1024 # 128 entries
> > >>
> > >> Qualquer orientação é bem vinda.
> > >>
> > >>
> > > Ate o FreeBSD 7 eu ate que me preocupava em ficar mexendo no hz. Apos
> > > isto, e com estas interfaces de rede modernas da Intel, nao me preocupo
> > > mais (nem com hz nem com polling) pois PARECE nao mudar muito coisa.
> > >
> > > Veja uma discussao de 2005 sobre o hz onde ja se discutia isto:
> > > http://lists.freebsd.org/pipermail/freebsd-questions/
> > > 2005-April/083482.html
> > >
> > > e veja tambem este link, na parte onde esta o hz o que ele diz:
> > > https://calomel.org/freebsd_network_tuning.html
> > >
> > >
> > > Edinilson
> > > ------------------------------------------
> > > ATINET
> > > Tel Voz: (0xx11) 4412-0876
> > > http://www.atinet.com.br
> > >
> > >
> > >
> > > -------------------------
> > > Histórico: http://www.fug.com.br/historico/html/freebsd/
> > > Sair da lista: https://www.fug.com.br/mailman/listinfo/freebsd
> > >
> > -------------------------
> > Histórico: http://www.fug.com.br/historico/html/freebsd/
> > Sair da lista: https://www.fug.com.br/mailman/listinfo/freebsd
>
> Pessoal,  pelo que compreendi, quanto mais alto o valor do HZ, mais rápido
> o sistema vai responder requisições de tarefas do kernel e do hardware.
> Embora como negativamente menor será o tempo disponível para limpar a
> sujeira de outro processo.
> Diminui a latência da rede e o tempo de resposta a uma requisição.
>
> Nesse sábado vou fazer uns testes aumentando o hz o máximo possível e ver
> como será o comportamento do sistema, depois posto os resultados.
>
> Contudo estou na dúvida de como fazer para verificar isso, o unixbench
> seria uma alternativa?
>
> Att.
> -------------------------
> Histórico: http://www.fug.com.br/historico/html/freebsd/
> Sair da lista: https://www.fug.com.br/mailman/listinfo/freebsd
>